Prime Minister Narendra Modi announced the commencement of India's first Air Quality Index (AQI) on April 6, this year. The index was launched to provide real time information on pollution levels in 10 cities, namely Delhi, Agra, Kanpur, Lucknow, Varanasi, Faridabad, Ahmedabad, Chennai, Bangalore and Hyderabad. On April 29, the Maninagar station recorded highest air pollution with 268 on AQI.

As per the Central Pollution Control Board's Air Ambient Quality Standard, the accepted level of PM 2.5 is 60 micrograms for 24-hour period. However, city crossed the 'very poor' performance by recording 364 micrograms at 4 am. Again, on May 15, the city registered highest average air pollution with 246 in AQI whereas Delhi recorded only 232. More shockingly, on May 2, the city crossed the danger limit line by recording 458 micrograms of PM 2.5 at 11pm.

These striking facts may have been cause for concern, but GPCB refuses to accept it. GPCB Secretary Hardik Shah said, "The online data only shows half the story. According to CPCB, the city is at 80th position in air pollution in the state." Regarding the WHO report of placing Ahmedabad as 5th most polluted city in the world, GPCB has written a letter to WHO. "They had misinterpreted the fact. It was recorded only on a single day when the air pollution increased due to unknown reasons," Shah said. The pollution parameters whose concentration is measured in ambient air include PM 2.5, PM 10, nitrogen dioxide, sulphur dioxide, carbon monoxide, ozone, ammonia and lead.